Pasteur

Louis Pasteur (December 27, 1822 – September 28, 1895) was a French chemist and microbiologist whose research in fermentation, germ theory, and vaccination established foundational approaches in medicine and industry. He developed pasteurization, a heat-based method to reduce microbial contamination in foods and drinks, and contributed to vaccines for several diseases, including anthrax and rabies.

Born in Dole, Jura, Pasteur studied science at the École Normale Supérieure in Paris and earned his doctorate in 1847. His early work centered on crystallography, notably the asymmetric nature of tartrate crystals, which helped establish the concept of optical isomerism and molecular asymmetry.

Pasteur's best-known investigations into fermentation showed that microbes, not air alone, drive the process; he demonstrated that specific organisms govern particular fermentation products. He used swan-necked flasks to show that boiled broth remained sterile unless contaminated, thereby refuting spontaneous generation and supporting the germ theory of disease.

Beyond theoretical work, Pasteur's methods transformed public health and industry. He devised pasteurization to prevent spoilage in wine, beer, and milk, applying heat to destroy pathogens while preserving properties. He developed vaccines for anthrax in animals and for rabies in humans, applying attenuation and immune principles. In 1887 he founded the Institut Pasteur, a research facility in Paris that bears his name and supports ongoing microbiology research.

His legacy lies in the consolidation of germ theory and promoting vaccines, antisepsis, and industrial microbiology, influencing medicine, agriculture, and food safety.